This is a note to let you know that I've just added the patch titled
driver core: add device probe log helper
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
driver-core-add-device-probe-log-helper.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 10c8424521598005444a9b2512f393bd01e0f2f2
Author: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Date: Mon Jul 13 16:43:21 2020 +0200
driver core: add device probe log helper
[ Upstream commit a787e5400a1ceeb0ef92d71ec43aeb35b1fa1334 ]
During probe every time driver gets resource it should usually check for
error printk some message if it is not -EPROBE_DEFER and return the error.
This pattern is simple but requires adding few lines after any resource
acquisition code, as a result it is often omitted or implemented only
partially.
dev_err_probe helps to replace such code sequences with simple call,
so code:
if (err != -EPROBE_DEFER)
dev_err(dev, ...);
return err;
becomes:
return dev_err_probe(dev, err, ...);
Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Reviewed-by: Mark Brown <broonie@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Link: https://lore.kernel.org/r/20200713144324.23654-2-a.hajda@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: 6d710b769c1f ("serial: sc16is7xx: add check for unsupported SPI modes during probe")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6e380ad9d08a..b66647277d52 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3334,6 +3334,48 @@ define_dev_printk_level(_dev_info, KERN_INFO);
#endif
+/**
+ * dev_err_probe - probe error check and log helper
+ * @dev: the pointer to the struct device
+ * @err: error value to test
+ * @fmt: printf-style format string
+ * @...: arguments as specified in the format string
+ *
+ * This helper implements common pattern present in probe functions for error
+ * checking: print debug or error message depending if the error value is
+ * -EPROBE_DEFER and propagate error upwards.
+ * It replaces code sequence:
+ * if (err != -EPROBE_DEFER)
+ * dev_err(dev, ...);
+ * else
+ * dev_dbg(dev, ...);
+ * return err;
+ * with
+ * return dev_err_probe(dev, err, ...);
+ *
+ * Returns @err.
+ *
+ */
+int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+
+ if (err != -EPROBE_DEFER)
+ dev_err(dev, "error %d: %pV", err, &vaf);
+ else
+ dev_dbg(dev, "error %d: %pV", err, &vaf);
+
+ va_end(args);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(dev_err_probe);
+
static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
{
return fwnode && !IS_ERR(fwnode->secondary);
diff --git a/include/linux/device.h b/include/linux/device.h
index bccd367c11de..0714d6e5d500 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1581,6 +1581,9 @@ do { \
WARN_ONCE(condition, "%s %s: " format, \
dev_driver_string(dev), dev_name(dev), ## arg)
+extern __printf(3, 4)
+int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
+
/* Create alias, so I can be autoloaded. */
#define MODULE_ALIAS_CHARDEV(major,minor) \
MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
